In Suzhou，Suzhou Pipeline Engineering Ltd. was working on Wuzhong Avenue stormwater pipe rehabilitation. Wuzhong Avenue sunk due to infiltration of 80” (DN2000) stormwater pipeline. The method of rehabilitation using chemical grout injection to fill the void and stop infiltration. Prior to injecting the chemical grout, contractor should use a tool to drill holes (diameter:DN25, depth:30cm) into the concrete pipe and soil by a workman in the pipe.

After visiting the jobsite and determining what was required to prevent the threat of dangerous working condition. WUXI HYDRO ENVIRONMENTAL TECH (WHET) representative recommended using one DOA underwater hammer drill HD13 with a standard bit attachment SDS-Max as the drill tool. One Trash pump SP35 was used to pump the infiltration water. DOA hydraulic tools offer an array of benefits including the power to weight ratio, durability and maintenance, zero tool exhaust, adaptable to all conditions (ability to safely operate in underwater condition). The contractor benefited from above features.